Automated testing systems may conduct clinical chemistry or assays using one or more reagents to identify an analyte or other constituent material in a specimen such as urine, blood serum, blood plasma, interstitial liquid, cerebrospinal liquids, and the like. For convenience and safety reasons, these specimens are almost always contained within specimen containers (e.g., specimen collection tubes). The test or assay reactions generate various changes that may be read and/or manipulated to determine a concentration of analyte or other constituent that is present in the specimen.
Improvements in automated testing technology have been accompanied by corresponding advances in pre-analytical sample preparation and handling operations such as batch preparation, centrifugation of sample containers to separate sample constituents, cap removal to facilitate fluid access, and the like by automated pre-analytical specimen preparation stations, which are part of Laboratory Automation Systems (LASs). LASs may automatically transport the specimens in specimen containers to a number of pre-analytical specimen processing stations and/or analytical stations containing clinical chemistry analyzers or assay instruments (hereinafter collectively referred to as “analyzers”).
These LASs may handle any number of different specimens contained in barcode-labeled specimen containers. The barcode label may contain an accession number that may be correlated to demographic information that may be entered into a hospital's Laboratory Information System (LIS) along with test orders and possibly other information. An operator may place the labeled specimen containers onto the LAS system in racks, and the LAS may automatically route the sample containers for pre-analytical operations such as centrifugation, de-capping, and possibly aliquot preparation, and all prior to the specimen actually being subjected to clinical analysis or assaying by one or more analyzers that may also be part of the LAS.
For certain tests, a serum or plasma portion (e.g., obtained from whole blood by centrifugation) may be used. A gel separator may be added to the specimen container to aid in the separation of the settled blood portion from the serum or plasma portion. After centrifuging and a subsequent de-capping process, the specimen container may be transported to an appropriate analyzer that may extract serum or plasma portion from the specimen container and combine the serum or plasma portion with one or more reagents in a reaction vessel (e.g., cuvette or other vessel). Analytical measurements may then be performed, often using a beam of interrogating radiation, for example, or by using photometric or fluorometric absorption readings, or the like. The measurements allow determination of end-point or rate or other values, from which an amount of analyte or other constituent to be determined using well-known techniques.
In the prior art, the integrity of the serum or plasma portion of the specimen is visually inspected by a skilled laboratory technician. This may involve a review of the color thereof. A normal serum or plasma portion has a light yellow to light amber color, and may not include clots, bubbles, or foam. Specimens containing Hemolysis, Icterus, or Lipemia (H, I, or L) may be determined by comparing the specimen to known color standards. However, manual visual inspection is very subjective, labor intensive, and fraught with the possibility of human error.
Because manual visual inspection includes the problems listed above, it is becoming increasingly prevalent to evaluate the integrity of specimens without the use of visual inspection by a laboratory technician, but rather by using an automated inspection. However, in some instances, barcode labels adhered directly to the specimen container may partially occlude a view of the specimen, so that there may not be clear opportunity to visually observe the serum or plasma portion of the specimen.
In some systems, such as those described in US Pat. Pub. 2012/0140230 to Miller, the specimen container may be rotated at a quality station to find a view window that is unobstructed by the label. However, such systems may be less prone to ease of automation.
Because of problems encountered when trying to rotate specimens for imaging, there is an unmet need for a method and apparatus adapted to readily image a specimen container and specimen. The method and apparatus should not appreciably adversely affect the speed at which analytical or assaying test results are obtained. Furthermore, the method and apparatus should be able to be used even on labeled specimen containers, where the label occludes the view of some portion of the specimen.